Measuring tape



Aug. 12, 1947.

E. J. WITCHGER" MEASURING TAPE Original Filed Nov. 24, 1959 ATTORNEYReiuued Aug. 12, 1947 MEASURING TAPE Eugene J. Witchger, Saginaw, Mich.,asslgnor to The Lufkin Rule Company, Saginaw, Mich., a corporation ofMichigan Original No. 2,314,915, dated March 30, 1943, Se-

rial No. 305,965, November 24, 1939.

Application for reissue October 9, 1944, Serial No.

11 Claims. 1

This invention relates to measuring tapesmade of ribbon metal, withprinted graduations and electroplated background areas.

Speaking generally, a novel principle is involved in my discovery ofunderlying causes of poor legibility, and short life in earlier tapes ofsuch character and in remedying the same.

It is concerned with process and structure features that bring aboutcertain newand useful improvements in respect to legibility andattractive appearance of such tapes, lasting sharpness of the edges ofthe markings; better color and other visual qualities of the unmarked orbackground areas, and greater durability of the finished article.

These and certain other objects which will be set forth in thespecifications have been attained not precisely by the improvement ofany specific element or step, but by a novel reorganization andco-operative working of several known,steps in unobvious sequence ororder. The results thus produced have not heretofore been suggested ordisclosed so far as I am aware.

The inventive novelty involved in various aspects of my improvement willbe more particularly pointed out in the following detailed descriptionand defined in the claims.

In the accompanying drawing:

Fig. 1 illustrates schematically a strip of polished ribbon metal afterhaving been given a punctulate or pitted surface of mat-like texturewherebyimproved physical and optical characterlsticsare imparted to thefinal outer surface of the finished product. f

Fig. 2 shows the strip, Fig. 1, after having been marked with numeralsand graduation characters;

Fig. 3 shows the strip, Fig. 2, after its background areas have beenplated with nickel or equivalent coating;

Fig. 4 shows the strip, Fig. 3, after having been provided with acoating of harder metal over the first plating;

Fig. 5 shows an alternative embodiment wherein a mat-surfaced strip,Fig. 1, has been rustproofed and the rust-proofed coating has beentreated preparatory to receiving a coating of metal;

Fig. 5a shows a further modification wherein the mat surface has beencreated by the rustproofing operation itself, and thentreated, as inFig. 5, to prepare for electroplating;

Fig. 6 shows the rust-proofed strip, Figs. 5 or 5a, with printedmarkings and plated background areas, this being a preferred structureand method for quantity production of high grade measuring tapes;

Figs. 7 to 13, inclusive. are enlarged and distorted cross-sectionalviews of the pieces shown in the respective adjacent Figs. 1 to 6, thesections being taken at place indicated by broken lines,

In the following description of my invention reference will be made toperforming various process steps on the "surface" of a stri of metal. Itwill be understood, however, that the terms "surface and face as appliedto the base ribbon metal strip are intended to designate all or any partof the surface areas of the strip, because I employ the invention in themanufacture of tapes that are coated on one face only, on part of aface, or on all surfaces.

Solely for convenience in terminology and not intended to be construedin a limiting sense, I shall designate certain surfaces as beingpunctulate," pitted or "mat-like," meaning that such a surface comprisesa multitude of uniformly distributed unevennesses, punctures, points,dots, or pits 2 of microscopic dimensions. The operation that producesthe surface will be called pitting."

The term markings designates graduation marks, figures, letters, orother characters on the tape. The term printing, inking," marking areintended to embrace any suitable or usual way of applying figures andgraduations to the tape, and more particularly figures and graduationsprinted in ink or the like that remain unplated when the remainder ofthe surface is plated. The unmarked areas are referred to as background.

I shall now explain my new process and the novel physical features ofthe product, incidental- 1y pointing out their advantages over earlierpractice, because correct appreciation of the novelty and advantages inuse of my new tape measure and the process for its manufacture requiresa brief exposition of disadvantages inherent in earlier tapes.

Considered each by itself the various facts underlying the recitedoperations have long been known, yet, so far as I am aware, they havenot been brought together in such a way as to produce measuring tapesthat possess the commercial and practical advantages attained by thisinvention.

In manufacturing a tape according to my method I provide a smooth metalribbon with a pitted or punctulate surface, mat-like in character, for Ihave discovered that the ribbon metal when pitted will impart to thefinished measuring tape several qualities hitherto unforeseen, adding toits value, usefulness and durability.

As a first step of my process therefore the customary polishedcommercial metal ribbon I, Figs.

1 and 7, may be subjected to a" treatment that gives its surface thedesirable punctulate or pitted quality. Such treatment may comprise, forexample, sand blasting, or spraying metal on the ribbon; or, preferably,subjecting the ribbon to mild etching by immersing it in approximately aten per cent solution of nitric acid for about fifty or sixty seconds,then cleaning the resulting pitted surface 2 by washing.

When the market shall offer a commercial ribbon metal with surfacesalready "pitted," as distinguished from the burnished and minutelyscored surfaces now commonly available, then it will no longer benecessary to perform a pitting operation as an initial step in themanufacture of tapes according to my process.

At this point it may be explained that what I have Just referred to asmild etching" is quite different from the deep etching heretoforeemployed in the manufacture of tapes wherein maskings were applieddirectly to the face of a ribbon and the residual areas or backgroundswere then etched to a depth that made the markings stand out in relief.Deeply etched tapes proved unsatisfactory in use, for they soon lost thecontrasty effect essential for easy reading. The mild etching or pittingoperations used by me give a velvet-like mat, 2, without creatingsurfaces in relief.

The second step, Figs. 2 and 8, is to apply conventional markings, 3, tothe pitted surface 2, using any ink or equivalent substance that willnot be damaged by solutions commonly used in electroplating. The ink isthen hardened rapidly at appropriate temperature, say, about 270 degreesFahrenheit, or, if preferred, more slowly at room temperature.

Some earlier tapes have been objectionable in that the markingsubstance, being printed directly upon a polished or burnished metalsurface, eventually blistered and flaked oif.

Preparing the ribbon surface by "pitting imparts unusually tenaciousholding power or tooth" for the ink substance. The markings becomedeeply and evenly incorporated as a permanent part of the ribbon. Theywill not scale off or flake and can not be worn away under conditions ofuse to such an extent as to destroy or even materially reduce thelegibility of the tape. Even perisistent scraping with a sharp tool willnot destroy such markings, but leaves the tape measure in usablecondition.

The third step, Figs. 3 and 9, is to electroplate those backgroundportions 4 of the pitted surface 2 which are not covered by the markings3; depositing thereon a light colored metal 5 such as nickel or silver.Electroplating does not take at all on the printed markings 3, but theexposed pitted or mat-like surfaces 2 take the plated metal 5 so deeplyand bond it so securely that the plate will not crack or craze when thetape is flexed, twisted or buckled in use.

The fourth step, Figs. 4 and 10, is to again electroplate the backgroundareas 4 with chromium or equivalent hard metal 6, imparting additionalstrength, durability, and hardness to the tape face and therebypreventing injury in use by scratching, rubbing, or impacts. Althoughthis fourth step, chrome plating as a second coat, is preferures whereextreme surface hardness is not a matter of great importance.

Having pointed out the great holding power of a pitted ribbon surfacefor the ink or marking substance, and its deep powerful bond for theplated metal on the background areas, I shall now describe an importantadditional and collateral advantage of providing a pitted ribbon surfacebeneath those places where marginal edges of the markings meet themarginal edges of the plating.

In earlier tapes with polished surfaces where margins of printedmarkings met edge to edge with the markins of a metal coating, flexingof the tape would eventually cause the meeting edges to separate farenough to let moisture get to the ribbon itself. Corrosion of theunderlying metal started and soon one or both of the meeting edges wouldbecome undermined and eventually gave way, the result being that thegraduations lost their sharp outlines and became fuzzy, blurred, andless easy to read.

The pitted surface, 2, Fig. 9, is helpful in preventing such defectsbecause it bonds so thoroughly with the ink markings 3 at their veryedges 3a, and likewise with the edges 5a of the electroplated coating 5,that separation of the meeting edges of ink 3 and plating 5 is lessliable to occur than in the earlier tapes alluded to.

Attainment of better optical characteristics has long been a bafllngproblem to manufacturers of measuring tapes, rules and the like, but Ihave discovered that which seems to have escaped the research of personsskilled in the art to which this invention pertains, namely, that highmetallic mirror-like refiectiveness from the finished backgroundsurfaces of a measuring tape, heretofore deemed an advantage, is in facta detriment, as will be understood from the following:

When a metal ribbon with burnished or polished surfaces is printed withgraduation markings 3 and is laid on a table and viewed from a shortdistance away and from different angles relatively to a light source,its unprinted areas act like mirrors. Thetape appears shiny, brilliant.or glary from some view points and duller and darker from othersaccording to the nature of the image which the unprinted areas mayhappen to Dark images present inadequate contrast with the markings,giving the tape poor legibility. Bright images cause glare that makesthe tape diflicult to read. The reflected surroundings sometimes produceundesirable variant light-and-dark effects at different places along inglengthwise, cause the ribbon surface to reflect the same aberrationsfrom light to dark with glare and poor legibility characterized the surface of the finished tape.

I have discovered a way of correcting such reflective defects. namely,by providing the ribbon with the previously described punctulate orhitted surface of mat-like texture.

The pitted surface on the ribbon imparts to the finish coating of thetape certain desirable characteristics not heretofore obtainable to suchextent, If at all. For example, a first coating of metal, I, plated onthe pitted surface will display a non-glary mat-like finish, and asecond coating of harder metal 6, Fig. 4, plated over its surface willbe free from harmful glare. For another example, I apply to the ribbonat single relatively thick plating of hard metal, in which event nofurther plating will be required to produce the desired results.However, nickel used as a first or filler coat is somewhat lessexpensive and is entirely suitable. In either event the thickness of theplated coating, or coatings, is preferably equal in thickness to, orslightly thicker than, the thickness of the ink or other coating used toprovide the graduation markings. This insures that the outer hard platedcoating which is much more wear resistant than the ink on the graduationmarking-s serves to protect the graduations from being rubbed off whenthe tape is in use.

Although surface refiectiveness is an important matter in metal tapemeasure production, there is another feature of almost equal importancwhich influences sales, and that is color or shade of the background. Ihave found that a minutely pitted surface 2 on the original ribbon Igives to the final chrome coating 6, Fig. 4, an unusual and veryattractive bluish-white color which gives effective contrast with darkcolored markings 3 and makes the tape measure more easily readable indim lighting.

A fifth and final step, also optional, is to coat the tape withtransparent lacquer,

A modification of the method set forth in the above five steps has to dowith rust-proofing the pitted or punctulate ribbon surface, as isindicated at '1, Figs. 5, 5a, 6, before the steps of marking and platingare performed. I

This rust-proofing step contributes important advantages and does'notadd unduly to the cost of manufacturing high grade measuring tapes and Iconsider it a preferable feature.

Rust-proofing may be accomplished by a known process bearing the tradenames Parker. izing" and Bonderizing. It comprises immersing the ribbonI in a heated solution that reacts on the metal surface, changing it toa phosphate coating 1 insoluble in water and resistant to corrosion.

After having been rust-proofed and printed, the unprinted portions ofthe surface present crystals or particles of phosphate that would tendto interfere with subsequent electroplating, causing it to craze, crack,or flake when bent and therefore experts have deemed it to becommercially impracticable to attempt to electroplate upon rust-proofedflexible ribbon measuring tapes. So, prior to my present invention tapemeasures with electroplated background areas were deprived of thebenefits of rust-proofing underneath the plate.

I have discovered a simple way of treating rust-proofed surfaces so theywill take electroplating perfectly and hold it permanently,

The treatment is in general described and claimed in my abandonedapplication, Serial No. 305,966, filed November 24, 1939 and copendingwith the original application for the present invention. A portion onlyof the adherent phosphate is removed from the phosphated surfaces, or atleast from those areas which are to be electroplated. Removal; may be byscrubbing with water, or with a dilute solution of muriatic acid. Thustreated, the resultant rust-proofed surfaces 8, Figs. 5, 5a, 6, have amat-like texture very like the pitted base surfaces 2, Figs. 1 and 7.which were produced by etching alone. The additional steps, marking,nickel-plating, and, if desired, chromeplating, may then be performed inany appropriate sequence.

This preferred modified method, rust-proofing a mat or pittedsurface andthen removing a portion only of the surplus rust-proofing material,produces good optical results in the finished tape measure, giving thefinal chromium coat 8, Figs.

4 and 6, a non-glary mat-like surface contrast. and the attractivebluish-white or silvery-white color which has been alluded to. It isresistant to corrosion and wear, and insures permanent sharpness of themeeting edges of the graduation markings and background plating.

A still further modification of my invention may comprise combiningrust-proofing and pitting in a single operation. I now draw attention tothis simplification of my invention, indicated schematically in Figs. 5aand 13.

Although better results are derived if pitting and rust-proofing arattained as separate steps in the manner already set forth, I have foundthat the rust-proofing operation alone will pit the surface of acommercial ribbon metal sufficiently to attain the major portion of theadvantages recited.

The ribbon having been rust-proofed, markings are then applied on therust-proof coating, after which the outer surface portion of th coatingof phosphate material is removed from the unprintedbackground areas inthe manner already described, and finally the thinned rustproofedsurface 9 is plated as in the preceding example.

The phosphatic coating which results from the rust-proofing instead ofhaving the hard, naturally repellent and impervious surface propertiesof the metal provides a surface which exhibits marked properties ofporosity and absorbency to which protective coatings such as paints,lacquers or the like are remarkably adherent.

While these adherent properties and advantages of rust-proofed surfacesindicated the use of rustproofing for electroplated articles, the artafter much experimentation found that metals which could otherwise beplated successfully could not be uniformly or satisfactorilyelectroplated after being rust-proofed, Hence it has generally beenbelieved that in spite of its desirability, rustproofing could not beused where it was necessary or desirable to electroplate the surface ofthe metal. the diillculty experienced in attempting to electroplaterust-proofed metals being due to the insulating or at least poorlyelectroconductivity of the phosphatic coating on the exposed surfaces ofthe metal resulting from the rust-proofing treatment. Consequently,although the desirability of using rust-proofed metal for measuringtapes has long been recognized, as it has long been standard practice toelectroplate the better quality metal tapes, it has been consideredimpossible to use rust-proofed metal in their construction.

I have found that in addition to the expected advantages from employinga rust-proofed base metal with its desirable anti-rusting properties,new, unexpected and exceptional results have been attained in the art ofconstructing metallic tape measures as follows:

(a) Due to the much greater porosity of the rust-proofed metal over theuntreated metallic ribbon stock, the printed ink markings are bonded sosecurely to the metal that they cannot be removed or impaired except bygrinding or scrapaaooa ing below the surface of the metal to which theyare affixed;

(b) The electroplated coatings are much more intimately and firmlyunited to the background or unmarked areas of the tape and will resistcrazing, cracking or peeling to a much greater extent thanelectroplated, non-rust-procfed tapes. I

() Separation of the margins or meeting edges of the printed andelectroplated areas as a result of flexing of the tape has been entirelyeliminated, and

(d) As the surface resulting from the rustprooflng is a dark minutelypunctulate one of mat-like texture the objectionable surface reflectionsof the polished ribbon tapes has been completely overcome.

It has heretofore been thought highly desirable to provide highlypolished surfaces on metal tape measures because the highly polishedmetal tape makes a very attractive appearing article having markedcustomer appeal and also the highly polished tape would tend to reduceundesirable friction eflects in coiling the tape within its casing, andfurthermore fo the purpose of facilitating cleaning the tape. I havediscovered, however, that which seems to have escaped the attention ofthose skilled in the art to which this invention appertains, namely,that instead of the highly polished tape being a desirable feature, itis highly undesirable.

I have also discovered that by producing the minutely pitted punctulatedsurfaces, the erratic optical effects hereinbefore referred to can beentirely obviated and thereby a tape of much greater legibillty beprocured but with entirely unexpected results from the standpoint ofmarkedly increased durability or longevity, while also producing anarticle of even greater attractiveness in appearance than the polishedtapes of the prior art. I

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A tape measure comprising a flexible strip of ribbon metal having atleast one face thereof provided with a mat-like minutely punctulatedarea, portions of said area having a coating penetrating into thepunctules thereof and a contrasting coating of rust resistant metalabutting said first mentioned coating and covering the entire remainingportions or said area, said metal coating providing a substantiallyglare free, light diffusing surface, one of said coatings constitutingmarkings including graduation markings and the other coatingconstituting a background area for said markings.

2. A tape measure comprising a flexible strip of ribbon metal having aportion of at least one face thereof provided with markings includinggraduation markings and another portion of said face provided with acontrasting coating of rust resistant metal abutting said markings andforming a substantially glare free light diffusing background for saidmarkings, said strip having a mat-like minutely punctulated areaextending continuously under said markings and coating, said markingsand coating covering all portions of said punctulated area and beingsecurely bonded thereto.

3. A measuring tap comprising a strip of thin flexible ribbon metalhaving at least one face thereof covered with minute pits to form anarea with substantially glare free light diffusing characteristics, aportion of said area being provided w h coa mark n s including raduationmarkings extending into said pits and being thereby securely bonded tosaid strip and the entire remaining portion of said area being providedwith an electroplated coating of a rust resistant metal intimatelyunited to, and bonded with, said strip and being of a thicknesssubstantially equal to the thickness of the coating forming saidmarkings.

4. A measuring tape comprising a strip of thin flexible ribbon metalhaving all portions of at least one face thereof provided with arust-proof coating to form a minutely pitted area having substantiallyglare free light diffusing characteristics, a minor portion of said areahaving superimposed thereon coated markings including graduationmarkings penetratin into said pits and being thereby securely bonded tosaid rustproof coating,and the entire major remaining portion of saidarea having superimposed thereon an electroplated coating of a rustresistant metal intimately united to, and bonded with, said rustproofcoating. I 5. A measuring tape comprising a strip of thin flexibleribbon metal having at least one face thereof provided with a rust-proofcoating to form a minutely pitted area having substantially glare freelight diffusing characteristics, a minor portion of said area havingsuperimposed thereon coated markings including graduation markingspenetrating into said pits and being thereby securely bonded to saidrust-proof coating, and the entire major remaining portion of said areahaving superimposed thereon an electrolytic coating of rust resistantmetal bonded to said rustproof coating and a second coating of harderrust resistant metal superimposed upon, and bonded to. said last namedmetal.

6. A steel measuring tape comprising a foundation member in the form ofa flexible ribbonlike strip of metal having at least one face thereofprovided with a rust resistant coating of greater porosity andabsorbency than naturally possessed by such metal and forming a minutelypitted area on said metal, a plurality of spaced coated markingsincluding graduation markings superimposed upon and intimately unitedwith said rust reslstant coating and covering a portion only of the areaof said rust resistant coating and an electroplated coating of rustresistant metal superimposed upon, and bonded to, the entire remainingarea of said rust resistant coating and cooperating with said markingsto provide a tape of substantially uniform thickness throughout itsentire width and length.

7. A measuring tape comprising a base strip of thin ribbon metal havingall portions of at least one face thereof treated to provide a glarefree area, mat-like in texture, formed of a multitude of minute pitsuniformly distributed over said entire area whereby said stripthroughout its entire length and width will be of substantially uniformthickness in all parts thereof, the minor portion of said area beingprovided with a nonmetallic coating consisting of a plurality of spacedmarkings including graduation markings and indicia superimposed uponsaid background and penetrating the same substantially to the full depthof said pits and the remaining portion of said area being provided withan electrolytic coating of a rust resistant and wear resistant metalintimately united with, and bonded to said strip and forming a glarefree contrasting surface for said markings, said electrolytic coatingbeing of substantially the same thickness as said nonmetallic coat ng toshield the latter from frictional wearing contact and forming a tightlyadherent Joint with the markings provided by said non-metallic coatingaround all of the meeting edges of said non-metallic and metalliccoatings.

8. A measuring device comprising a metallic strip a surface of which isprovided with an indicia area and a background area, the surface of oneof said areas being colored, the other area of the metallic strip havinga matte surface and an outer coating or metal on the said last namedsurface and which has assumed the matte characteristics of the underlyinmatte surface.

9. A measuring device comprising a metallic strip a surface of which isprovided with an indicia area and a background area, colored reactionproducts of a metal disposed upon one of said areas, the other area ofthe metallic strip having a matte surface and an outer coating of metalon the said last named surface and which has assumed the mattecharacteristics of the underlying matte surface.

10. A measuring device comprising a metallic strip a surface of which isprovided with indicia areas and background areas, the surface of theindicia areas being colored, the background areas of the metallic striphaving a matte surface and an outer coating of metal thereon which hasassumed the matte characteristics of the underlying matte surface andprovides legible contrast with said colored indicia areas.

11. A measuring device comprising a metallic strip a surface of which isprovided with indicia areas and background areas, colored reactionproducts of a metal disposed on said indicia areas. the background areasof the metallic strip having a matte surface and an outer coating ofmetal thereon which has assumed the matte characteristics of saidunderlying matte surface and provides legible contrast with said coloredindicia areas.

EUGENE J. WITCHGER.

